This invention relates to nozzle arrangements for fluid delivery heads which, for example, may be of the pop up variety whether used in swimming pools, lawn sprinklers, or the like, wherein it is desired to rotationally index the nozzle head intermittently with the application of fluid, for example, liquid pressure. During the intermittent operation the stream of liquid flowing from the nozzle opening covers the full circumference or any desired part of the area involved. It is an object of the invention to provide an improved rotational indexing nozzle arrangement of this character.
Indexing nozzles, or similar apparatus, are known to the prior art, and specifically are known in the applicant's co-pending application above referred to. Reference may also be made in this connection U.S. Pat. No. 3,408,006 Stanwood issued on Oct. 29, 1968 and entitled "Liquid Jet Producing Device". In the applicant's co-pending application indexing is achieved by virtue of the liquid under pressure flowing through diagonally disposed passageways which flow causes the nozzle component to rotate. At the same time, the force of the liquid causes the nozzle head to pop up, and when it has rotated sufficiently engagement between appropriate surfaces takes place and rotation of the nozzle is stopped. In the Stanwood patent the application of fluid pressure likewise causes the nozzle head to pop up against the force of an appropriately placed spiral spring and when the fluid pressure is cut off the nozzle head recedes to its rest position. In so doing, appropriate cam surfaces interengage and cause the nozzle head to rotate by a specified amount.
In the prior art devices, particularly those referred to above, operation has not been totally satisfactory. In a structure according to the applicant's application. Ser. No. 082,182, relatively erratic dwell time in the rotational indexing of the sprinkler heads is achieved on occasion. Possibly this is due to time or pressure variations in the pipe or plumbing network feeding the sprinkler nozzles. In the Stanwood U.S. Pat. No. 3,408,006 the mechanism for causing indexing of the rotational nozzle head is relatively complicated and also subject to erratic performance. The latter may occur because of the cam surfaces involved which may become encrusted with rust or other deposits from the water, particularly from the chemicals involved in maintaining swimming pools, or the like.
Accordingly, it is a further object of the invention to provide an improved rotational indexing nozzle arrangement which overcomes the defects of the prior art devices and the environments wherein such devices are used.